We all may have heard the saying GNS3 is great for practicing routing labs but switching Nah Nah!! Don’t underestimate the power of GNS3. It has a special IOU feature which will let you emulate real Cisco Switch both L2 & L3 in GNS3 without any trouble.

If you want to know what is an IOU? Refer to this excellent article here else follow along…

For you to access them easily I am making all the “rare files” available for you here : http://bit.ly/IOUGNS3

Let us now go through the step by step process to configure IOU in GNS3:

Install the GNS3-IOU .ova file in Virtual Box. Make Sure you don’t have any older version of IOU installed in it.

Start the VM. It may take a few moments to run at the first time.

After it has started, you will note an IP address shown above the console screen. In my case it was: 192.168.56.101:8000/upload where 192.168.56.101 was the IP of the VM which was the Host-Only adapter of the Virtual Box instance.

Next open your web browser and go to http://192.168.56.101:8000/upload.

Select the L2 and L3 IOU image one by one and click on the upload button. The full path will be shown after uploading is completed.

Now open GNS3. Goto edit->preferences.

Click IOS on Unix. Under path to IOURC put D:\GNS3 IOU\IOURC.txt (the location of IOURC.txt file).